When T 34 got in to combat with German counterparts during the first months of the war in the summer of 1941 it was found at once as expected, that it was quite insufficient to work the German tanks properly. It was then provided with a better (and longer) 76.2-mm gun for better effect. Two (and better) periscopes were put on top of the turret. The production had difficulties finding rubber to the wheels and some vessels had (noisy) iron wheels (see picture). The hull was made 76 cm longer making it possible to store more ammunition for the machine gun.